test: Support tests which can only be run manually

At present we normally write tests either in Python or in C. But most
Python tests end up doing a lot of checks which would be better done in C.
Checks done in C are orders of magnitude faster and it is possible to get
full access to U-Boot's internal workings, rather than just relying on
the command line.

The model is to have a Python test set up some things and then use C code
(in a unit test) to check that they were done correctly. But we don't want
those checks to happen as part of normal test running, since each C unit
tests is dependent on the associate Python tests, so cannot run without
it.

To acheive this, add a new UT_TESTF_MANUAL flag to use with the C 'check'
tests, so that they can be skipped by default when the 'ut' command is
used. Require that tests have a name ending with '_norun', so that pytest
knows to skip them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/cmd_ut.c b/test/cmd_ut.c
index dc88c5f..beebd5c 100644
--- a/test/cmd_ut.c
+++ b/test/cmd_ut.c
@@ -19,16 +19,26 @@
 		    int argc, char *const argv[])
 {
 	int runs_per_text = 1;
+	bool force_run = false;
 	int ret;
 
-	if (argc > 1 && !strncmp("-r", argv[1], 2)) {
-		runs_per_text = dectoul(argv[1] + 2, NULL);
+	while (argc > 1 && *argv[1] == '-') {
+		const char *str = argv[1];
+
+		switch (str[1]) {
+		case 'r':
+			runs_per_text = dectoul(str + 2, NULL);
+			break;
+		case 'f':
+			force_run = true;
+			break;
+		}
 		argv++;
 		argc++;
 	}
 
 	ret = ut_run_list(name, prefix, tests, n_ents,
-			  argc > 1 ? argv[1] : NULL, runs_per_text);
+			  argc > 1 ? argv[1] : NULL, runs_per_text, force_run);
 
 	return ret ? CMD_RET_FAILURE : 0;
 }
diff --git a/test/dm/test-dm.c b/test/dm/test-dm.c
index eb35813..66cc2bc 100644
--- a/test/dm/test-dm.c
+++ b/test/dm/test-dm.c
@@ -36,7 +36,7 @@
 	int ret;
 
 	ret = ut_run_list("driver model", "dm_test_", tests, n_ents, test_name,
-			  runs_per_text);
+			  runs_per_text, false);
 
 	return ret ? CMD_RET_FAILURE : 0;
 }
diff --git a/test/py/conftest.py b/test/py/conftest.py
index 304e931..fc9dd3a 100644
--- a/test/py/conftest.py
+++ b/test/py/conftest.py
@@ -289,7 +289,13 @@
         m = re_ut_test_list.search(l)
         if not m:
             continue
-        vals.append(m.group(1) + ' ' + m.group(2))
+        suite, name = m.groups()
+
+        # Tests marked with _norun should only be run manually using 'ut -f'
+        if name.endswith('_norun'):
+            continue
+
+        vals.append(f'{suite} {name}')
 
     ids = ['ut_' + s.replace(' ', '_') for s in vals]
     metafunc.parametrize(fixture_name, vals, ids=ids)
diff --git a/test/test-main.c b/test/test-main.c
index 2323cba..ddfd89c 100644
--- a/test/test-main.c
+++ b/test/test-main.c
@@ -508,6 +508,30 @@
 
 		if (!test_matches(prefix, test_name, select_name))
 			continue;
+
+		if (test->flags & UT_TESTF_MANUAL) {
+			int len;
+
+			/*
+			 * manual tests must have a name ending "_norun" as this
+			 * is how pytest knows to skip them. See
+			 * generate_ut_subtest() for this check.
+			 */
+			len = strlen(test_name);
+			if (len < 6 || strcmp(test_name + len - 6, "_norun")) {
+				printf("Test %s is manual so must have a name ending in _norun\n",
+				       test_name);
+				uts->fail_count++;
+				return -EBADF;
+			}
+			if (!uts->force_run) {
+				if (select_name) {
+					printf("Test %s skipped as it is manual (use -f to run it)\n",
+					       test_name);
+				}
+				continue;
+			}
+		}
 		old_fail_count = uts->fail_count;
 		for (i = 0; i < uts->runs_per_test; i++)
 			ret = ut_run_test_live_flat(uts, test, select_name);
@@ -529,7 +553,7 @@
 
 int ut_run_list(const char *category, const char *prefix,
 		struct unit_test *tests, int count, const char *select_name,
-		int runs_per_test)
+		int runs_per_test, bool force_run)
 {
 	struct unit_test_state uts = { .fail_count = 0 };
 	bool has_dm_tests = false;
@@ -563,6 +587,7 @@
 		}
 		memcpy(uts.fdt_copy, gd->fdt_blob, uts.fdt_size);
 	}
+	uts.force_run = force_run;
 	ret = ut_run_tests(&uts, prefix, tests, count, select_name);
 
 	/* Best efforts only...ignore errors */